Bugfix: "degree 3" models were actually being fit with degree=2
Exclude BHS from all model fits and evaluation.

The data for the Bahamas looks suspect.  It's unusually high for the
first decade or so of the data, and then it disappears entirely.  It's
hard to be sure exactly what's going on here, so we just exclude it.
Replace BHS with ARE in the list of testing countries.

Having removed BHS, we really needed to replace it in the testing
data.  Additionally, BHS was the only high cement production country
in the testing dataset; all of the others are in the training set.
Emirates has the highest cement production of anyone, so putting it in
the testing set should serve as a kind of a stress test for the
modeling procedure.  Of course, once we start doing actual n-way cross
validation, this won't be such a problem.
Add the nostock model to the ones printed at the end of the fitting.